Michigan senator Arthur Vandenburg’s admonition at the beginning of the Cold War that American politics would stop at the water’s edge seems downright quaint in today’s political environment. In fact, politics never stops at the water’s edge, and never has, but there was at least a respect for bipartisanship efforts on foreign policy matters in Vandenberg’s day. Not today.

You won’t find even a nod in that direction now. Consider an article in the current Foreign Policy by Karl Rove and Ed Gillespie, two veteran political operatives and top aides to President George W. Bush. The piece is a primer on how President Obama’s GOP opponent should attack him on foreign policy issues—including the current war in Afghanistan—in the coming general election campaign.

The authors want the Republican candidate—presumably former Massachusetts governor Mitt Romney—to "condemn the president’s precipitous drawdown in Afghanistan." What kind of advice is that? The latest CNN/ORC Poll asked respondents whether they favor or oppose the U.S. war in Afghanistan. Opposition hit 71 percent. Fully 69 percent said the United States "should not be involved now" in that war. Asked whether the war had been a U.S. success, 59 percent said no.

Messrs. Rove and Gillespie apparently haven’t figured it out yet, but the Republicans are heading for a buzz saw on this issue. The rhetoric throughout the GOP nomination battle reflected a similar sentiment. But you can’t conduct a war with nearly three quarters of the voters opposed to it. Obama seems to understand this, which is why he’s working so assiduously to fashion a pullout strategy that could get the troops home in some kind of orderly way. He has slipped into plenty of missteps, but his overall efforts clearly have been consonant with voter sentiments.

That’s the problem with this kind of partisan slashing, particularly on foreign policy. The passion for pugilism often shrouds political realities that can come back to haunt the slasher. Romney would be wise to ignore such advice contained in this howler of a political primer.